SIP / H.323 / IAX telephone customization 3 rd term presentation Brendan Marlborough Supervisor: Alfredo Terzoli

Contents Some background to VoIP devices Some background to VoIP devices The hardware structure of the phone The hardware structure of the phone The software structure The software structure What I have done What I have done What I must do What I must do

Background The telecommunications industry is shifting towards using VoIP The telecommunications industry is shifting towards using VoIP Needs VoIP technology Needs VoIP technology People are used to normal telephones People are used to normal telephones

VoIP Device History First software phone was written in 1995, and many more have made an appearance. First software phone was written in 1995, and many more have made an appearance. Phone adapters – converts POTS to ethernet Phone adapters – converts POTS to ethernet VoIP phones VoIP phones

Hardware structure Consists of: Controller PA1688 Processor DSP Other interfaces for Flash Memory SDRam AC97 Audio Ethernet

Hardware components Controller Controller Controls memory interface and sdram Controls memory interface and sdram CPU CPU Intel MCS8051 at 50MHz Intel MCS8051 at 50MHz DSP DSP ADSP2181 at 33MHz ADSP2181 at 33MHz Flash Memory Flash Memory 1Mb, used to store program memory and initializing data 1Mb, used to store program memory and initializing data

Hardware components SDRam SDRam 16Mb, Ac97 buffers TCP/IP router info, dialled calls etc. 16Mb, Ac97 buffers TCP/IP router info, dialled calls etc. AC97 Codec AC97 Codec Encodes / Decodes audio at 8Khz Encodes / Decodes audio at 8Khz

Software structure Uses bank switching Uses bank switching Allows programs to be bigger than the cpu can address Allows programs to be bigger than the cpu can address Written in c and compiled to MCS 8051 instruction set Written in c and compiled to MCS 8051 instruction set Libraries have recently been made open source Libraries have recently been made open source

Program Flow

Compiler Keil 7 Keil 7 Free version only compiles object files up to 2kb Free version only compiles object files up to 2kb Full version +- R10000 Full version +- R10000 Other free 8051 compilers such as SDCC Other free 8051 compilers such as SDCC Palmtool used to generate bin file Palmtool used to generate bin file

What I have done Done background research which has culminated into the ‘literature review’ Done background research which has culminated into the ‘literature review’ Studied the chip in detail Studied the chip in detail Looked through the code and gained a basic understanding Looked through the code and gained a basic understanding Installed and tested a windows version of asterisk on my pc Installed and tested a windows version of asterisk on my pc Got the code partially to compile Got the code partially to compile

What I have to do Decide what must be changed about the phone and implement it Decide what must be changed about the phone and implement it Some ideas Some ideas LED shows something user selectable when on idle (might need updating web interface) LED shows something user selectable when on idle (might need updating web interface) Time of the day / message waiting Time of the day / message waiting Display fetches info of web such as temperature Display fetches info of web such as temperature Re-write some of the documentation in better English Re-write some of the documentation in better English Do final write-up Do final write-up

Thank you Questions? Questions?